Comparison of a cavity antenna with stacked patches and a metasurface-inspired design

The objective of this work is to demonstrate and compare two solutions for increasing the bandwidth performance of cavity type antennas having an aperture size close to half the operating wavelength and placed in a large (infinite) ground plane. As an example, we chose a square cavity geometry with size 0.475 × 0.475 × 0.15 λ
₀
at 2.3 GHz. To excite the antenna, we placed inside the cavity volume first a stacked-patch configuration and then a metasurface-inspired design, both producing two resonances around the central frequency of 2.3 GHz. We discuss benefits of the metsurface design in terms of bandwidth performance, design and manufacturing complexity, as well as the total cost.